1. Field of the Invention
The disclosure generally relates to an antenna system, and more particularly, relates to an antenna system with high isolation characteristics.
2. Description of the Related Art
With progress in mobile communication technology, mobile devices, for example, portable computers, mobile phones, tablet computer, multimedia players, and other hybrid functional portable electronic devices, have become more common To satisfy the demand of users, mobile devices usually can perform wireless communication functions. Some functions cover a large wireless communication area, for example, mobile phones using 2G, 3G, and LTE (Long Term Evolution) systems and using frequency bands of 700MHz, 850MHz, 900MHz, 1800MHz, 1900MHz, 2100MHz, 2300MHz, and 2500MHz. Some functions cover a small wireless communication area, for example, mobile devices using WLAN (Wireless Local Area Networks), Bluetooth, and WiMAX (Worldwide Interoperability for Microwave Access) systems and using frequency bands of 2.4GHz, 3.5GHz, 5.2GHz, and 5.8GHz.
To make a mobile device operate in multiple bands, an antenna designer should dispose a plurality of antennas in the mobile device. Since these antennas are close to each other, mutual interference is generated, and the radiation performance thereof is degraded.